RFR: 8350111: [PPC] AsyncGetCallTrace crashes when called while handling SIGTRAP [v3]

[Martin Doerr]

On Wed, 26 Feb 2025 14:06:20 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

>> With this change `JavaThread::pd_get_top_frame_for_profiling()` fails if the current thread is found to be `_thread_in_Java` but the CodeCache does not contain its pc.
>> 
>> This will prevent crashes as described by the JBS item.
>> 
>> The fix might be too conservative for situations where a thread doen't change its thread state when calling native code, e.g. using the Foreign Function & Memory API. The difficulty finding a less defensive fix is that one must detect if a valid pc can be found in the caller's ABI before constructing that frame.
>> 
>> Testing:
>> 
>> * DaCapo Tomcat with async-profiler on a fastdebug build.
>> * Tier 1-4 of hotspot and jdk on the main platforms and also on Linux/PPC64le and AIX.
>
> Richard Reingruber has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Improve whitespace

Marked as reviewed by mdoerr (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/23641#pullrequestreview-2644793700